Leuco derivative of diethylgallocyanin.



UNITED STATES Pi-{DENT QFFICE.

WILHELM LOMMEL, OF ELBERFELD, GERMANY, ASSIGNOR TO FARIBENFABRIKEN VORlVI. FRIEDR. BAYER & CO. OF ELBERFELD, GERMANY, A CORPORATION OF Patented June 14, 1910.

GERMANY.

LEUCO DERIVATIVE OF DIETHYLGALLOCYANIN.

961,361. Specificationof Letters Patent. No Drawing. Application filed February 19, 1910'.

To all whom, it may concern:

Be it known that I, 'imiizmi LOMHEL, I doctor of philosophy, chemist, citizen of the German Empire, residing at lllberi'eld, (ier- 'niany, have invented new and useful linprovements in New Leuco Derivatives from Diethylgallocyanin, of which the following carboxylated leuco-gallocyanin derived from nitrosodimethylanilin and gallic acid. The gallocyanin derived iroiu nitrosodiethylanilin and ;'allic acid is not particularl process hitherto known for the production of these compounds it cannot be obtained in technical yields. for its production which consistsin using Serial No. 544,869.

action is tested from time to time and thereacticn is complete when on repeated test- 'ingitis found that after the addition of sod um carbonate and oxidation of the precipit'ated leuco compound by air the dyeis precipitated by the addition of common I i i I yellowish-brown color. des ribed and my experience is that by the salt.

The hydrochlorid of the new leuco com- I pound forms after drying and powdering a dark powder easily soluble in water with a On adding sodium acetate or sodium carbonate to the aqueous solution of the hydrochloric acid salt the free base separates out which oxidizes. very I have t'ound 'a process 2 for the condensation salts of the nitroso compound of dietliylauilin with such acids 1 as form with the nitroso compound dillicultly soluble salts.

I have now found that a new leuco derivativc of a coloring matter of the oxazin.

rapidly on exposure to air. The new .leuco compound dissolves in concentrated sulfuric acid with. a reddish-yellow color. It yields upon oxidation the color described in my other application for Letters Patent of same oxidation is soluble-inhydrochloric acid of 1 20 136. with a pure blue color and is iiisoluble in sodium carbonate solution. These tests readily distinguish the new dyefrom leiico-dietliylgallocyanin which J'ttt oxida tion is soluble in sodium carbonate solution and dissolves in hydrochloric acid of it)" B. with a red color. 1

Th0 following example will further illustrate my invention, the parts being; by weiglitz- 236.5 parts of the' diethylgallocyanin dye (obtained by the action of nilroso i lictliylaiiilin on gallic acid) are reduced with 9 parts of zinc dust and liyulrochlo rice acid and the liltercd solution is then heated forsoiiic hours to 93-100 U.,'caiie being taken to prevent the access at air as much as possible. The product of the redate from which it can be produced by reduction.

I claim:

The hcrcin-described new leiieo compound being chemically decarboxylated leueo-dicthylgaIlocyaiiin, which is in the shape of its hydrochloi'nl a dark powder which after oxidation is insoluble in sodium carbonate solution and dissolves in hydrochloric acid of 20 156. with a pure blue color and which new lcuco compound is easily soluble in water with a \'cllowisli-brown color, soon illllllllg blue in consequence of oxidation; dissolving in concentrated sulfuric acid with a redlish- \'ellow color; the free base being separated by the addition of sodium carbonate to the aqueous solution of the hydrochlorid, substantially as liereinbeft'ire descril-z-d.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. \V l Ll IE I'IM LOMMEL. [n is] \Vitncsses: O'rro Kiinnn. 1

WViLIn' KLEIN. Y 

